EP2032245A1

EP2032245A1 - Reactor for the production of c2 to c8 olefins from an oxygenate, water vapor, and one or more material flows containing hydrocarbon

Info

Publication number: EP2032245A1
Application number: EP07724448A
Authority: EP
Inventors: Hermann Bach; Lothar Brehm; Jürgen BOHLE; Gunter Quass; Günther Heinz; Katja Bartels; Heinrich DÖRR; Harald KÖMPEL
Original assignee: Lurgi GmbH
Current assignee: Air Liquide Global E&C Solutions Germany GmbH
Priority date: 2006-06-03
Filing date: 2007-04-21
Publication date: 2009-03-11
Anticipated expiration: 2027-04-21
Also published as: ATE531446T1; CN101460239A; CN101460239B; EP2032245B1; DE102006026103A1; DE102006026103B4; WO2007140844A1; US20100063337A1; US8444940B2

Abstract

A reactor is described for the production of C2 to C8 olefins from gaseous oxygenate and H2O and one or more material flows containing C2 C4, C5, C6, C7, C8 olefin and paraffin at 400° to 470° C., wherein several reaction stages which the material flow can pass through from the top to the bottom, each consisting of a support base with a catalyst layer situated on it, are arranged in a closed, upright container. In order to be able in each case to lower the temperature of the reaction mixture leaving the reaction stages before it enters into the next reaction stage, it is provided that each support base consists of cells which are placed closely next to each other with no gaps and which are securely attached to each other and filled with catalyst, and in the space formed by two neighboring reaction stages, respectively, an assembly of nozzle tubes is installed for spraying a liquid phase containing H2O and DME and/or MEOH, using a water-saturated gas phase containing mainly DME and/or MEOH, in the direction of the following reaction stage downstream.

Description

Reactor for the production of C ₂ - to C ₈ -olefins from an oxygenate, water vapor and one or more hydrocarbons-containing stream

The invention relates to a reactor for producing C ₂ - to C ₈ - olefins, preferably propylene, from gaseous oxygenate, preferably dimethyl ether (DME) and / or methanol (MEOH), and H ₂ O and one or more of the hydrocarbons C ₂ - , C ₄ -, C ₅ -, C ₆ -, C ₇ -, C ₈ - olefins and paraffins containing, a temperature of 400 to 470 ° C having stream, with several arranged within a closed, stationary container, from the stream from top to bottom flowed through reaction stages, each consisting of a support base with a thereon, formed from a bed of kömigem molecular sieve catalyst fixed bed zone. The invention also relates to a method for operating the reactor.

From DE-A-102 33 975 an apparatus for the production of propylene from MEOH is known. In this case, a gaseous feed stream of MEOH / DME and water at operating temperatures of 250 to 460 ° C over several, vertically arranged in a vertical vessel above one another from top to bottom flowed through by the feed stream reaction stages. The reaction stages each consist of a support, a grid supported thereon with a mesh size of 1/4 ^" and an overlying 300 mm thick layer of SiO ₂ - or Al ₂ O ₃ balls, on a 750 mm thick layer of a shape-selective catalyst pentasil-type cylindrical 1/16 ^" and 1/8 ^" long cylindrical bodies overlaid with a 200 mm thick layer of 1/2 ^" diameter ceramic balls and a wire mesh placed thereon. The reaction of the feed stream at the reaction stages takes place at inlet temperatures of 400 to 460 ⁰ C and pressures of 0.5 to 3.0 bar. To cool the reaction mixture emerging from the reaction stages, heat exchangers are arranged between the reaction stages, by means of which the reaction mixture is cooled to a temperature of from 400 to <460 ° C. in each case. The cross section of the inlet openings of the heat exchangers corresponds in each case to the cross section of the outlet openings of the preceding reaction stage. The product stream derived from the container is turned into a DME, H ₂ O. and MEOH-containing liquid phase and a hydrocarbon-containing gas phase separated and separated from the hydrocarbons propylene. The disadvantage of this method is the fact that the reaction in the reaction stages is not isothermal and the cooling of the reaction mixture by means of the heat exchangers located between the reaction stages is structurally relatively complicated and fluidly unfavorable.

It is therefore the object of the present invention to construct the reactor described in the introduction and to carry out the process for operating the reactor so that the temperature of the reaction mixture emerging from the individual reaction stages is as a result of the exothermic course of reaction in the range from 400 to 500 ° C. before entering the downstream next reaction stage to a temperature of 380 to 470 ° C lower. In addition, the introduction of the catalyst layer is to be simplified in the individual reaction stages and the flow through the catalyst layer can be improved.

This object is achieved in that each tray is constructed of juxtaposed freely spaced, firmly interconnected cells and suspended freely in the container, the cells are filled with a layer of molecular sieve catalyst, each in the two adjacent reaction stages up and down limited space a nebulizer system in the form of a crowd of nozzle tubes for the uniform spraying of a DME and / or MEOH containing, consisting mainly of H ₂ O, a temperature of 25 to 150 ° C having liquid phase by means of a water-saturated, mainly DME and / or MEOH containing a temperature of 170 to 300 ° C having gas phase is provided in the direction of the next downstream reaction stage downstream. By spraying the liquid phase, the temperature of the reaction mixture leaving the reaction stage at a temperature of 400 to 500 ° C is lowered to a value of 380 to 470 ° C, so that the course of the reaction is quasi-isothermal. The liquid phase can contain up to 30% by volume DME and / or MEOH and the gas phase up to 80% by volume DME and up to 30% by volume MEOH.

Synthetic zeolites of various types, for example ZSM-5, pentasil, MFI-Z or MeAPSO are used in particular as molecular sieve catalysts. The grains of the molecular sieve catalyst are preferably cylindrical and have a mean length of 3.5 to 7.0 mm or 2.1 to 4.5 mm and an average diameter of 3.1 to 3.4 mm or 3.3 to 3.7 mm.

In the context of the particular embodiment of the invention, the layer thickness of the filled into the cells of the tray molecular sieve catalyst is 100 to 1000 mm and downstream of a reaction stage to the next reaction step steadily, wherein expediently the layer thickness of the first Reaktioπsstufe 100 to 500 mm and that the last reaction stage is 500 to 1000 mm. By this measure and by the adaptation of the material flow amounts a constant for the exothermic reaction residence time of the reaction mixture is guaranteed in all reaction stages.

The support base constructed of numerous cells, preferably in the shape of cuboids, cubes or straight, equilateral prisms, has sufficient flexural rigidity against the total weight formed from its own weight, the weight of the layer of molecular sieve catalyst and the weight of the inert balls. The size of the deflection of the tray is negligible and ensures a free suspension of the tray in the container.

So that the molecular sieve catalyst and the underlying 100 to 400 mm thick layer of inert spheres can not fall out of the cells, the bottom of the support floor has a wire mesh, expanded metal, perforated sheet-like or similar designed covering. The diameter of the inert balls is 10 to 15 mm in the lower layer section and 5 to 8 mm in the upper layer section. Such a layer structure prevents formation of flow channels through which the reaction mixture can prematurely escape from the reaction stage.

Cover surface side of the support floor also has a wire mesh, streckrnetall-, perforated plate-like or the like formed cover on which a 50 to 200 mm thick layer of inert balls is placed with a diameter of 5 to 15 mm. The arrangement of this layer ensures that the liquid phase sprayed in the intermediate space formed by two adjacent reaction stages is reliably and completely vaporized.

According to a particular embodiment of the invention, the atomizer system consists in each case of a family of nozzle tubes with two-component nozzles arranged at regular intervals, with external mixing, preferably with full cone characteristics, with a jet angle from 15 to 35 ° C. The external mixing of gas and liquid phase, the flow rate of predominantly H ₂ O and DME and / or MEOH containing, a temperature of 25 to 150 ° C having liquid phase and the water-saturated, predominantly DME and MEOH-containing, a temperature of 170 to 300 ° C having gas phase independently set.

In one embodiment of the invention, the atomization system respectively mounted between two adjacent reaction stages consists of each of two sides of a vertical plane enclosing the container axis horizontally inserted from the periphery of the container, arranged in mirror image, closed at the ends lying in Strömungsrichtuπg nozzle tubes, each perpendicular to the the container axis enclosing vertical plane are routed parallel to each other at a regular distance and the distance of the nozzle tube ends to the container axis enclosing the plane is 20 to 500 mm. By this arrangement it is achieved that the free path of the liquid is limited. ^'

An optimal cooling effect by the sprayed liquid phase can then be achieved if the cube or parallelepiped design of the cells forming the support base, the nozzle tube of each lying on a straight double or single cell wall has the same distance and arranged extending in the cell wall enclosing this vertical plane is.

In special cases, it is possible to lay the nozzle tubes in the form of circle involutes.

To operate the reactor, a gaseous oxygenate, preferably DME and / or MEOH, as well as containing H ₂ O, a temperature of 150 to 300 ° C-containing process stream cooled to a temperature of 100 to 160 ° C, separated into a liquid phase and a gas phase and liquid phase and gas phase into a plurality of partial streams, the number of which corresponds in each case to the number of intermediate spaces between the reaction stages, divided. With reference to a gap, in each case one gas phase partial stream is fed to a nebulizer after heating to a temperature of 170 to 300 ° C. and a liquid phase partial stream is cooled to a temperature of 25 to 150 ° C. and sprayed into the intermediate space , As a result of these measures, the inlet temperature of the reaction mixture emerging from the reaction stage into the interspace can be adjusted to the desired temperature before it enters the next reaction stage. In order to achieve a complete vaporization of the liquid phase, it is appropriate to rupture the liquid phase by means of the gas phase into a fine droplet spectrum with a diameter of 10 to 100 μm.

The invention is explained below by way of example and in the drawings closer and by way of example.

Show it:

Fig. 1 is a process flow diagram with schematically illustrated reactor

Fig. 2 is a plan view of a constructed of cuboid cells supporting base

Fig. 3 is a plan view of a constructed of honeycomb cells support base

4 is a plan view of a support base formed by cuboidal cells in a container with nozzle tubes arranged above it. FIG. 5 is a plan view of the support base according to FIG. 4 with the base surfaces of the spray cones generated by the installed two-substance nozzles FIG Form of circle involuted crowd of atomizers with the bases of the built-in two-fluid nozzles

Spray cones Fig. 7 is an enlarged section (X) of FIG. 1

According to Fig. 1, the reactor (1) consists of a vertical, cylindrical, closed container (2) with six mutually integrated reaction stages (3, 4, 5, 6, 7, 8), in detail, as in Fig. 2 to Fig. 5 and reproduced in Fig. 7 section (X) shown in Fig. 1, from a free-carrying support base (9) of parallelepiped, ground and cover surface side with a wire mesh (10, 11) covered, free space firmly connected together Cells (12) are constructed. The lower portion of the cells (12) is filled with a 100 mm thick layer (13) of ceramic spheres whose diameter is 0.5 ^" in the lower half of the layer and 0.25" in the upper half of the half. On this spherical layer (13) is piled up a layer (14) of granular shape-selective zeolite catalyst of the pentasil type. On the cover surface side arranged wire cloth (11) is a 100 ± 10 mm thick layer (15) of ceramic balls with a diameter of 0.25 ^" From the top of the container takes downstream the thickness of the catalyst layer (14) from reaction stage to reaction stage ( 3, 4, 5, 6, 7, 8), in the downstream first reaction stage (3) the layer thickness is 253 ± 10 mm, in the second reaction stage (4) 286 ± 10 mm, in the third reaction stage (5) 327 ± 10 mm, the fourth reaction stage (6) 384 ± 10 mm, the fifth reaction stage (7) 462 ± 10 mm and the sixth Reaction step (8) 588 ± 10 mm. FIG. 3 shows a support base (9) constructed from honeycomb cells (16). The Schichtdickeπ are variable.

In the by the reaction stages (3, 4, 5, 6, 7, 8) limited spaces (17, 18, 19, 20, 21) in each case a crowd of nozzle tubes (22, 23, 24, 25, 26) with in At regular intervals inserted therein two-fluid nozzles (27) laid with external mixing and full cone characteristic with a beam angle of 30 °. The two-fluid nozzles (27) atomize the flowing through the tube (28) consisting predominantly of water, DME and MeOH containing a temperature of 93 ° C containing liquid phase under the action of the supplied introduced via the pipe (29), an average temperature of 175 ⁰ C. possessing water-saturated, DME and MEOH containing gas phase. The two-fluid nozzles (27) allow a uniform spraying of the liquid phase in the form of aerosols. The large specific surfaces of the liquid phase produced by the spraying enable rapid heat and mass transfer between the aerosols on the one hand and the reaction mixture leaving the reaction stages (3, 4, 5, 6, 7) on the other hand.

As shown in Fig. 4, each of the two adjacent reaction stages (3, 4, 5, 6, 7, 8) limited space (17, 18, 19, 20, 21) mounted atomizer system consists of both sides of a the vertical axis (30) enclosing the container axis and inserted from the periphery of the container (1) in a horizontal plane, arranged in mirror image, closed at the ends lying in the flow direction nozzle tubes (22, 23, 24, 25, 26) perpendicular to the container axis enclosing vertical plane (30) at a regular distance paraWe) are laid to each other. The individual nozzle tubes (22, 23, 24, 25, 26) each have the same distance from the straight-lying walls of the cells (12) and are arranged to extend in the vertical planes enclosing the cell walls.

Fig. 5 shows the base surfaces (31) of the full cone produced by the two-fluid nozzles of the nozzle tubes (22, 23, 24, 25, 26).

For special applications is shown in FIG. 6, the possibility to move the nozzle tubes in the form of Kreis involunti.

When operating the reactor, the container (2) at the top via line (32) has a temperature of 469 ° C, gaseous stream of 104199 kg / h, consisting essentially of 1819 kg MEOH, 3721 kg DME ₁ 41841 kg of water and 56753 kg of hydrocarbons, abandoned. From the bottom of the container (2) via line (33) is a Temperature of 480 ° C, gaseous stream of 155405 kg / h, consisting essentially of 443 kg MEOH, 217 kg DME ₁ 72450 kg of water and 79879 kg of hydrocarbons, deducted.

Via line (34) a feed stream of 51207 kg / h, containing 9724 kg of MEOH, 29266 kg of DME and 12200 kg of water and having a temperature of 156 ° C, in a condenser (35) passed. The cooled to a temperature of average 150 ⁰ C feed stream is fed via line (36) to a two-phase separator (37), in which a separation into a gas phase flow of 44832 kg / h, in detail consisting of 8497 kg MEOH ₁ 29229 kg DME and 7089 kg of water and a liquid phase flow of 6375 kg / h, composed of 1227 kg of MEOH, 38 kg of DME and 5110 kg of water. The gas phase stream discharged via line (38) is subdivided into five sub-streams which in each case flow via one of the lines (39, 40, 41, 42, 43) into plate heat exchanger (44) and are heated therein to a temperature of 176 ° C. become. The liquid phase stream leaving the two-phase separator (37) via line (45) is cooled in a heat exchanger (46) to a temperature of 93 ° C., discharged via line (47) and separated into five partial streams. Of the gas phase partial streams discharged from the plate heat exchangers (44) via the lines (48, 49, 50, 51, 52), a respective gas phase partial stream and from the via the lines (53, 54, 55, 56, 57 ) liquid phase partial streams each have a liquid phase partial stream each supplied to a nozzle tube (22, 23, 24, 25, 26) and the liquid phase under the action of the gas phase uniformly in the direction of the downstream next reaction stage (4, 5, 6, 7, 8) sprayed in the form of aerosols. By an additional heat exchanger (46) immediately downstream, not shown heat exchanger, the temperature of the liquid phase stream can be lowered to 25 ° C.

In detail, the liquid phase partial stream fed via line (57) is 800 kg / h, essentially containing 171 kg of MEOH, 5 kg of DME, 713 kg of H ₂ O, and the gas phase partial stream of 6259 kg supplied via line (52) / h, essentially containing 1186 kg of IvIEOH ₁ 4080 kg of DME and 990 kg of H ₂ O, fed to the nozzle tube (22) and sprayed into the intermediate space (17) between the first and second reaction stages (3, 4). The via line (56) discontinued liquid phase partial flow of 1019 kg / h, consisting essentially of 196 kg MEOH, 6 kg DME and 817 kg H ₂ O, and via line (51) supplied gas phase partial flow of 7167 kg / h containing essentially 1358 kg of MEOH, 4673 kg of DME and 1133 kg of H ₂ O, are fed to the nozzle tube (23) and the liquid phase is sprayed into the intermediate space (18) between the second and third reaction stages (4, 5). \ n the limit of the third and fourth reaction stage (5, 6) The intermediate space (19) is supplied via line (55) liquid phase partial flow of 1197 kg / h, containing essentially 230 kg MEOH ₁ 7 kg DME and 959 kg H ₂ O ₁ of the via line (50) supplied gas phase substream of 8417 kg / h, essentially containing 1595 kg of MEOH, 5488 kg of DME and 1331 kg of H ₂ O ₁ sprayed. The via line (54) the nozzle tube (25) supplied liquid phase partial flow of 1438 kg / h, essentially containing 277 kg MEOH ₁ 9 kg DME and 1153 kg H ₂ O ₁ is by means of the line (49) the nozzle tube (26 ) supplied gas phase partial stream of 10111 kg / h, consisting essentially consisting of 1926 kg MEOH ₁ 6592 kg DME and 1599 kg H ₂ O ₁ in the fourth and fifth reaction stage (6, 7) limited space (20) sprayed. In the intermediate space (21) formed by the fifth and sixth reaction stages (7, 8), the liquid phase partial stream supplied via line (53) to the nozzle tube (26) is 1831 kg / h, essentially containing 351 kg of MEOH, 11 kg of DME and 1468 kg H ₂ O ₁ by means of the line (48) to the atomizer (27) supplied gas phase partial stream of 12879 kg / h, essentially containing 2441 kg MEOH ₁ 8397 kg DME and 2037 kg H ₂ O sprayed.

The dual-fluid nozzles used have an external mixture, i. Gas and liquid phase component streams each occur separately and meet directly at the nozzle outlet. The gas phase strikes the solid jet emerging from the liquid nozzle mouthpiece jet outside the nozzle and tears this to a fine droplet spectrum. The regulation of the gas phase partial streams has almost no influence on the volumes of the liquid phase partial streams. This also applies to the change in the liquid-phase volume partial flows with effect on the gas phase partial flows.

Claims

claims:

1. A reactor for the preparation of C ₂ - to C ₈ -olefins, preferably propylene, from gaseous oxygenate, preferably dimethyl ether (DME) and / or methanol (MEOH) ₁ and H ₂ O and one or more of the hydrocarbons C ₂ , - -) -, C ₅ -, C ₆ -, C ₇ -, C ₈ - containing olefins and paraffins, a temperature of 400 to 470 ° C having stream, with several within a closed, standing container (2) arranged from the reaction stages (3, 4, 5, 6, 7, 8) flowing through from above, each consisting of a support base (9) with a fixed bed zone formed thereon of a layer (14) of granular molecular sieve catalyst, characterized in that each tray (9) is made up of juxtaposed, freely interconnected cells (12, 16) and freely suspended in the container (2), the cells being filled with a layer (14) of molecular sieve catalyst, respectively that of two be adjacent reaction stages (3, 4, 5, 6, 7, 8) up and down limited space (17, 18, 19, 20, 21) an atomizing system in the form of a crowd of nozzle tubes (22, 23, 24, 25, 26 ) for the uniform spraying of a DME and / or MEOH-containing, mainly consisting of H ₂ O, a temperature of 25 to 150 ° C having liquid phase by means of a water-saturated, predominantly DME and / or MEOH-containing, having a temperature of 170 to 300 ° C. Gas phase is provided in the direction of the downstream reaction stage following.

2. Reactor according to claim 1, characterized in that the molecular sieve catalyst is a synthetic zeolite, for example of the ZSM-5 type, pentasil type, MFI-Z type or MeAPSO type.

3. Reactor according to one of claims 1 and 2, characterized in that the grains of the molecular sieve catalyst are cylindrical and have an average length of 3.5 to 7.0 mm or 2.1 to 4.5 mm and an average diameter of 3.1 to 3.4 mm or 3.3 to 3.7 mm.

4. Reactor according to one of claims 1 to 3, characterized in that the thickness of the layer (14) of the in the cells (12, 16) molecular sieve catalyst is 100 to 1000 mm and downstream of a reaction stage (3, 4, 5, 6, 7, 8) increases steadily to the next reaction step.

5. Reactor according to claim 4, characterized in that the thickness of the layer (14) in the cells (12, 16) molecular sieve catalyst of the first reaction stage (3) 100 to 500 mm and the downstream last reaction stage (8) 500th up to 1000 mm.

6. Reactor according to one of claims 1 to 5, characterized in that the support base (9) forming cells (12, 16) have the shape of a cuboid, a cube or a straight equilateral prism.

7. Reactor according to one of claims 1 to 5, characterized in that the support base (9) on the bottom and top surface side has a wire mesh, expanded metal, hole-sheet-like or the like shaped cover (10, 11).

8. Reactor according to one of claims 1 to 6, characterized in that in the cells (12, 16) of Tragbσdeπs (9) has a 50 to 400 mm thick layer (13) inert balls whose diameter in the lower portion of the layer 10th to 15 mm and in the upper section 5 to 8 mm, is, on which the layer (14) of molecular sieve catalyst is poured.

9. Reactor according to one of claims 1 to 7, characterized in that on the cover surface overlap (11) of the support base (9) a 50 to 200 mm thick layer (15) inert balls is applied with a diameter of 5 to 15 mm.

10. Reactor according to one of claims 1 to 8, characterized in that the nozzle tubes (22, 23, 24, 25, 26) arranged at regular intervals two-fluid nozzles with external mixing, preferably with full cone characteristic with a beam angle of 15 to 35 ° have.

11. Reactor according to one of claims 1 to 9, characterized in that the atomizer from each of both sides of a vertical axis enclosing the container axis (30) from the periphery of the container (1) inserted, arranged in mirror image, at the lying in the direction of flow ends closed nozzle tubes (22, 23, 24, 25, 26), each perpendicular to the container axis enclosing the vertical plane are routed at regular intervals and the distance of the nozzle tube ends to the container axis enclosing the vertical plane is 20 to 500 mm.

12. Reactor according to claim 10, characterized in that in the case of a cuboid or parallelepipedal design of the cells (12) forming the support base (9), the individual nozzle tubes (22, 23, 24, 25, 26) are each of cell walls lying on a straight line has the same distance and in which the cell walls enclosing vertical plane are arranged to extend.

13. Reactor according to one of claims 9 and 10, characterized in that the respective one crowd forming nozzle tubes are laid in the form of Kreis involuntic.

14. A process for the operation of the reactor (1) for the preparation of C ₂ - to C ₈ -olefins, preferably propylene, from a gaseous oxygenate, preferably DME and / or MEOH ₁ and H ₂ O and one or more of the hydrocarbons C ₂ - , C ₄ -, C ₅ -, C ₆ -, C ₇ , C _B - containing olefins and paraffins, a temperature of 400 to 470 ° C having stream, with several within a closed, standing container (2) arranged, of the reaction streams (3, 4, 5, 6, 7, 8) flowing through from above, each consisting of a support base (9) with a fixed bed zone formed thereon of a layer (14) of granular molecular sieve catalyst, wherein each support tray is made up of juxtaposed, freely interconnected, tightly interconnected cells (12, 16) and freely suspended in the container, the cells being filled with the molecular sieve catalyst layer, each in two adjacent reactions 17, 18, 19, 20, 21) have an atomizing system in the form of a group of nozzle tubes (22, 23, 24, 25, 26) for uniformly spraying a predominantly H ₂ O containing temperature 50 to 150 ° C having liquid phase by means of a water-saturated, predominantly DME and / or MEOH containing, having a temperature of 170 to 300 ° C gas phase in the direction of the respective downstream reaction stage is provided, characterized in that a gaseous oxygenate, preferably DME and MEOH, as well as containing H ₂ O, a temperature of 150 to 300 °

Cooled C-containing feed stream to a temperature of 100 to 150 ° C and separated into a liquid phase and a gas phase, the gas and liquid phase into several partial streams, the number of each of the number of reaction stages between (3, 4, 5, 6, 7 , 8) existing intermediate spaces (17, 18, 19, 20, 21) corresponds, divided and the single gas phase partial stream, each with a liquid phase partial flow a nozzle tube (22, 23, 24, 25, 26) abandoned and the liquid phase by means of Gas phase is sprayed into the corresponding space.

15. The method according to claim 13, characterized in that the liquid phase is torn by means of the gas phase to a fine droplet spectrum with a diameter of 10 to 100 microns.